Somatostatin and (D-Trp8, D-Cys14)-somatostatin delay extinction and reverse electroconvulsive shock induced amnesia in rats.

In the present study the effects of somatostatin and its analogs on active avoidance behavior, electroconvulsive shock (ECS)-induced retrograde amnesia, and spatial-discrimination learning were compared in rats. (D-Trp8, D-Cys14)-somatostatin (as did the somatostatin molecule itself) delayed the extinction of active avoidance behavior, antagonized ECS-induced amnesia, and did not modify spatial-discrimination learning. Des-Asn5-(D-Trp8, D-Ser13) somatostatin and des-AA1,2,4,5,12,13,-(D-Trp8) somatostatin did not influence these behaviors. The data suggest that certain parts of the somatostatin molecule are important for its behavioral actions.